The answer to 'why is my P-trap slow draining' is that a clogged or obstructed P-trap is the most common cause of slow draining. The P-trap is the curved pipe under your sink that helps prevent sewer gases from entering your home. Over time, hair, soap scum, and other debris can build up in the trap, restricting water flow and causing slow drainage.
Some common symptoms of a clogged P-trap include water taking a long time to drain, the sink gurgling, or a foul odor coming from the drain. To fix a slow-draining P-trap, you can try using a plunger or a drain snake to clear the blockage. If that doesn't work, you may need to disassemble the trap and clean it manually. However, if the clog is severe or you're not comfortable doing the work yourself, it's best to call a professional plumber.